Inkjet head manufacturing method

ABSTRACT

An inkjet head manufacturing method is disclosed. The method of manufacturing an inkjet bead including a plurality of chambers, configured to contain ink; and an actuator, configured to provide pressure to the chamber, which includes forming a piezoelectric element on one side of the inkjet head that is adjacent to the chambers; forming the actuator(s) by dicing the piezoelectric element such that the piezoelectric element is divided and placed corresponding to a position of the chamber(s); and etching one side of the inkjet head such that a part of the piezoelectric element remaining between the adjacent actuators, can manufacture an inkjet head having a thin-film actuator reducing the cross talk by removing a part of the piezoelectric element remaining between the actuators of the inkjet head.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.10-2008-0106925, filed with the Korean Intellectual Property Office onOct. 30, 2008, the disclosure of which is incorporated herein byreference in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to a method of manufacturing an inkjethead.

2. Description of the Related Art

The inkjet printer can convert an electric signal to a physical forceand discharge an in ink droplet through a nozzle in order to perform theprinting. An inkjet head can be manufactured by processing variouselements such as a chamber, a restrictor, a nozzle, and a piezoelectricelement on each layer and coupling the layers to one another.

The inkjet head has been expansively applied to the manufacture ofelectronic parts, such as printed boards and LCD panels, as well as theconventional graphic inkjet industries that perform the printing on thepaper or fiber.

Accordingly, the inkjet printing technology for electronic parts, whichis required to discharge functional ink more precisely than theconventional graphic printing, requires functions that the conventionalinkjet has not required. It is necessary to control the size and thespeed deviation of an ink droplet. Moreover, high density nozzles andhigh frequency properties are required to increase the production. Anactuator of the thin-film inkjet head has been developed to meet suchdemands.

FIG. 1 is a front cross-sectional view showing a conventional inkjethead 12. In accordance with the conventional art as shown in FIG. 1, apiezoelectric element is adhered to one surface of the inkjet head 12,and then dicing is performed to allow the piezoelectric element tofunction as an independent actuator 2 on each chamber 6.

At this time, if each of the actuators 2 is completely severed, theremay be serious stress on a silicon board of the inkjet head 12. If thepiezoelectric element is not completely severed, however, the adjacentactuators 2 are connected to each other, thereby causing the crosstalk.

If the dicing is performed twice by using a saw blade for fear of thestress of the silicon board of the inkjet head 12, there remains awall-shaped part 8 of the piezoelectric element between the adjacentactuators, thereby causing the crosstalk.

SUMMARY

The present invention provides a method of manufacturing an inkjet headhaving a thin actuator and reducing the crosstalk.

An aspect of present invention features a method of manufacturing aninkjet head, the inkjet head having a plurality of chambers containingink and an actuator providing pressure to the chambers, includingforming a piezoelectric element on one side of the inkjet head that isadjacent to the chambers; forming the actuator(s) by dicing thepiezoelectric element such that the piezoelectric element is divided andplaced corresponding to a position of the chamber(s); and etching oneside of the inkjet head such that a part of the piezoelectric elementremaining between the adjacent actuators is removed.

Here, the forming of the piezoelectric element can be performed byadhering the sintered piezoelectric element to one side of the inkjethead.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front cross-sectional view showing the conventional inkjethead;

FIG. 2 is a lateral cross-sectional view showing an inkjet head inaccordance with an embodiment of the present invention;

FIG. 3 is a flowchart showing an inkjet head manufacturing method inaccordance with an embodiment of the present invention;

FIG. 4 and FIG. 5 are plan views showing an inkjet head in accordancewith an embodiment of the present invention;

FIG. 6 is a front cross-sectional view showing an inkjet head inaccordance with an embodiment of the present invention; and

FIG. 7 and FIG. 8 are front cross-sectional views showing part of aninkjet head in accordance with an embodiment of the present invention.

DETAIL DESCRIPTION

The features and benefits of an embodiment of the present invention willbecome more apparent through the below description with reference to theaccompanying drawings.

An inkjet head manufacturing method according to an embodiment of thepresent invention will be described in detail with reference to theaccompanying drawings. Identical or corresponding elements will be giventhe same reference numerals, regardless of the figure number, and anyredundant description of the identical or corresponding elements willnot be repeated.

FIG. 2 is a lateral cross-sectional view showing an inkjet head inaccordance with an embodiment of the present invention. As shown in FIG.2, an inkjet head 100 can include a reservoir 111, a restrictor 113, achamber 114, a membrane 115, an actuator 190, and a nozzle 116.

The reservoir 111 can contain ink and supply the ink to the chamber 114through the restrictor 113, which will be described below. The reservoir111 can receive ink from the outside of the inkjet head 100 through aninlet 112. The inlet 112 and the chamber 114 can be formed on a thirdplate 30, and the reservoir 111 can be formed or, a second plate 20.

The restrictor 113 can connect the reservoir 111 and the chamber 114,which will be described below, and function as a channel supplying theink from the reservoir 111 to the chamber 114. The restrictor 113 andthe reservoir 111 can be formed on the second plate 20.

The restrictor 113 can have a cross-section that is smaller than that ofthe reservoir 111. When pressure is provided to the chamber 114 by theactuator 190, the restrictor 113 can adjust the amount of the inksupplied from the reservoir 111 to the chamber 114.

One side of the chamber 114 can be connected to the restrictor 113, andthe other side can be connected to the nozzle 116. The chamber 114 canbe formed inside the inkjet head 100 to receive ink, and the membrane115 can cover the one side of the membrane 115.

A plurality of inkjet heads can be formed in the widthwise directioninside the inkjet head 100. Accordingly, a plurality of reservoirs 111can be formed by being expanded in the widthwise direction, and each ofthe restrictors 113 can be formed between each chamber 114 and thereservoir 111.

The nozzles 116 can be connected to the other side of each chamber 114and provide a path through which ink is discharged to the outside of theinkjet head 100. The nozzle 116 can be formed on a first plate 10.

The actuator 190 can be coupled to one side of the inkjet head 100,corresponding to a position of the chamber 114, which is an upper sideof the membrane 115. The actuator 190 can provide pressure to thechamber 114 by generating vibration and transferring the vibration tothe chamber 114 through the membrane 115. The membrane 115 can be formedon a fourth plate 40.

An upper electrode (not shown) and a lower electrode (not shown) can becoupled to one side of the inkjet head 100 in order to supply voltage tothe actuator 190.

The above-described inkjet head 100, including the nozzle 116, thechamber 114, the restrictor 113, and the reservoir 111, can be formed bystacking the first plate 10, the second plate 20, the third plate 30,and the fourth plate 40, on which each of the corresponding elements areformed. The first plate 10, the second plate 20, the third plate 30, andthe fourth plate 40 can be made of a silicon board. The method ofmanufacturing the inkjet head 100 in accordance with an embodiment ofthe present invention will be described below.

FIG. 3 is a flowchart showing an inkjet head manufacturing method inaccordance with an embodiment of the present invention. As shown in FIG.3, the method of manufacturing the inkjet head 100 in accordance with anembodiment of the present invention can include a process represented byS100, in which a sintered piezoelectric element 400 is adhered to oneside of the inkjet head 100 that is adjacent to the chamber 114; aprocess represented by S200, in which the actuator 190 is formed bydicing the piezoelectric element, to correspond to a position of thechamber 114; and a process represented by S300, in which one side of theinkjet head 100 is etched such that a part of the piezoelectric element400 remaining between the adjacent actuators 190 is removed.Accordingly, by removing a part of the piezoelectric element 400 thatremains between the actuators 190 of the inkjet head 100, it is possibleto manufacture the inkjet head 100 having the thin actuator 190 thatreduces the crosstalk.

FIG. 4 and FIG. 5 are plan views showing an inkjet head in accordancewith an embodiment of the present invention. As shown in FIG. 4, in theprocess represented by S100, the sintered piezoelectric element 400 canbe adhered to one side of the inkjet head 100 adjacent to the chamber114.

The chamber 114 can be formed inside the inkjet head 100. The sinteredpiezoelectric element 400 can be adhered to one side, which is an upperside, of the inkjet head 100 adjacent to the chamber 114.

The sintered piezoelectric element 400 can have a bulk shape. Thebulk-shaped piezoelectric element 400 can be adhered to the upper sideof the inkjet head 100, corresponding to the position of the chamber114. The piezoelectric element 400 can be adhered to the upper side ofthe inkjet head 100 by using, for example, an adhesive.

Next, in the process represented by S200, the actuators 190 can beformed by dicing the piezoelectric element 400 such that thepiezoelectric element 190 remains between the actuators 190, which areto be adjacently formed corresponding to the position of each of thechambers 114, as shown in FIG. 5. As described above, the chambers 114can be arranged side by side in the widthwise direction of the inkjethead 100, and the dicing process can sever and divide the piezoelectricelement 400 such that the actuator 190 is formed on each chamber 114.

FIG. 6 is a front cross-sectional view showing an inkjet head inaccordance with an embodiment of the present invention. As shown in FIG.6, the dicing process can be performed one time to divide thepiezoelectric element 400, to thereby form the adjacent actuators 190.This can prevent a wall-shaped part of the piezoelectric element 400from remaining between the adjacent actuators 190.

The dicing process can be also performed to be shallow enough not toserver the piezoelectric element 400 completely. Accordingly, it ispossible to minimize the stress on the fourth plate 40 in the process ofcompletely severing the piezoelectric element 400.

FIG. 7 and FIG. 8 are front cross-sectional views showing part of aninkjet head in accordance with an embodiment of the present invention.Through the dicing process, the thickness of the piezoelectric element400 remaining between the adjacent actuators 190 may be identical tothat of the actuator 190, which is to be removed through the etching asdescribed below, as shown in FIG. 7. Accordingly, it is possible toremove a part of the piezoelectric element 400 remaining between theadjacent actuators 190 and simultaneously form the actuators havingdesired thicknesses.

Next, in the process represented by S300, one side of the inkjet head100 can be etched such that a part of the piezoelectric element 400remaining between the adjacent actuators 190 is removed. The etchingprocess can be preformed by, for example, wet etching. The etchingconditions can be adjusted such that the actuators 190 can be physicallyseparated from one another by removing a part of the piezoelectricelement 400 remaining between the adjacent actuators 190. Varioussolutions capable of etching the piezoelectric element 400 can be usedas the etchant. For example, it is possible to use a solution having thecomposition of 1BHF:2HCl:4NH4Cl:4H2O.

Accordingly, the method of manufacturing the inkjet head 100 inaccordance with an embodiment of the present invention can separate theadjacent actuators 190 by complementing the limitations of the dicingprocess, which is a mechanical method, with the etching process, whichis a chemical method. This can give no stress to the fourth plate 40 butcan prevent the crosstalk from being generated, thereby improving thedischarging property of the inkjet head 100.

On the other hand, the etching process can be performed over the overallpart of one side of the inkjet head 100. The process of forming anadditional etching resist on one side of the inkjet head 100 can beomitted. Accordingly, it is possible to remove a part of thepiezoelectric element 400 remaining between the adjacent actuators 190and simultaneously reduce the thickness of the actuator 190.

As a result, it is possible to decrease the actuating voltage of theinkjet head 100 and improve the frequency property of the inkjet head100 because the thin actuator 190 can be formed even though the sinteredbulk-shaped piezoelectric element is used.

Hitherto, although some embodiments of the present invention have beenshown and described for the above-described objects, it will beappreciated by any person of ordinary skill in the art that a largenumber of modifications, permutations and additions are possible withinthe principles and spirit of the invention, the scope of which shall bedefined by the appended claims and their equivalents.

1. A method of manufacturing an inkjet head, the inkjet head including aplurality of chambers containing ink and an actuator providing pressureto the chambers, the method comprising: forming a piezoelectric elementon one side of the inkjet head that is adjacent to the chambers; formingthe actuator(s) by dicing the piezoelectric element such that thepiezoelectric element is divided and placed corresponding to a positionof the chamber(s); and etching one side of the inkjet head such that apart of the piezoelectric element remaining between the adjacentactuators is removed.
 2. The method of claim 1, wherein the forming ofthe piezoelectric element is performed by adhering the sinteredpiezoelectric element to one side of the inkjet head.